Now add one more to that list. A newly discovered life form lives in deep, boiling hot water near hydrothermal vents in the ocean. On formate. That's what's left when formic acid loses a hydrogen ion.

The organism, known as Thermococcus onnurineus NA1, belongs to the group known as archaea, some of the simplest organisms on the planet, similar to bacteria and stretching back to the dawn of evolutionary history. It's also the newest extremophile, or life form that thrives in extreme environments.

Scientists thought formate was too poor an energy source to support life. But these archaea do fine. Getting useful energy from formate is now the simplest way known for any life form to get its fuel, though it relies on the absence of oxygen. That makes it rare on Earth today but it also shows that life can find a way, even under the harshest conditions.

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